old suburban gravity furnace question

[fred wark]

model GT 6 3A When the valve beneath the white temperature control knob reacts to the ambient temp, as measure by the thermopile, should the fuel supply to the burner simply shut completely off, until things cool down enough for the thermopile to call for more heat and then the burner gets relit? Or should this valve only reduce or increase the fuel supply with the burner being constantly on, and adjusting itself as required? Thanks

[panhead_mike]

Does this help any?
https://www.manualslib.com/manual/10...3a.html#manual

[billmccracken]

Originally Posted by fred wark

model GT 6 3A When the valve beneath the white temperature control knob reacts to the ambient temp, as measure by the thermopile, should the fuel supply to the burner simply shut completely off, until things cool down enough for the thermopile to call for more heat and then the burner gets relit? Or should this valve only reduce or increase the fuel supply with the burner being constantly on, and adjusting itself as required? Thanks

I believe the main burner shuts down completely when the set temp is reached. The pilot flame should stay lit so that the burner can relight when the temperature falls again. If the pilot flame doesn’t stay lit the cause is most likely that the thermocouple needs to be replaced.
Hope this helps. It’s the way most older gas heating appliances work - before electronic ignition and power vented appliances were developed.

[fred wark]

thanks mike and bill

[Mike_L]

The pilot light, controlled by the thermocouple, should stay lit all the time to light the burner when necessary. The main burner lights when heat is called for.